1. Field of the Invention
The present invention relates to a transaxle device and, more particularly, to the structure of the transaxle device.
2. Description of the Related Art
A vehicle including a plurality of traveling driving sources such as a hybrid vehicle or a plug-in hybrid vehicle has conventionally been known. The hybrid vehicle or the plug-in hybrid vehicle includes an engine and a motor as the traveling driving sources. As such a hybrid vehicle or a plug-in hybrid vehicle, a vehicle has been developed that is capable of driving in a parallel driving mode for simultaneously driving wheels with driving forces of both of the engine and the motor.
As the hybrid vehicle or the plug-in hybrid vehicle, for example, there is a vehicle in which the engine and the motor are arranged side by side in the left-right direction in a front part of the vehicle and drive a drive shaft connected to front wheels via a transaxle device.
For example, a configuration has been known in which an engine shaft arranged coaxially with an engine, a generator shaft to which a motor and a generator are connected, and an idler shaft connected to a drive shaft via a differential gear are arranged in parallel to one another (see Japanese Patent No. 4958126). In the generator shaft, an inner circumferential shaft to which the generator is connected and an outer circumferential shaft to which the motor is connected are integrally configured to be capable of relatively rotating. The inner circumferential shaft is driven by the engine. The engine shaft includes a clutch that connects and disconnects transmission of power of the engine that drives the drive shaft via the idler shaft and the differential gear.
In a series mode for generating electric power in the generator with the power of the engine and causing the vehicle to travel with the power of the motor, the clutch included in the engine shaft is disconnected, the generator is driven by the power of the engine via the engine shaft and the inner circumferential shaft, and the drive shaft is driven by the power of the motor via the differential gear, the idler shaft, and the outer circumferential shaft. In a parallel mode for causing the vehicle to travel with the power of the engine and the power of the motor while driving the generator with the power of the engine to generate electric power, the clutch included in the engine shaft is connected to transmit the power of the engine to the drive shaft via the engine shaft, the idler shaft, and the differential gear.
In a driving device for a hybrid vehicle disclosed in the patent publication, the clutch is disposed in the engine shaft provided between an output gear for transmitting the power of the engine to the inner circumferential shaft and an output gear for transmitting the power of the engine to the idler shaft.
However, when a clutch is disposed between the output gears included in the engine shaft in this way, since a mounting space for the clutch is reduced, a freedom of design of the clutch decreases. Further, the engine shaft is long in the axial direction and the transaxle device is long in the engine shaft direction. Therefore, for example, in a vehicle in which an output shaft of the engine extends in the vehicle width direction of the vehicle, since the transaxle device is long in the vehicle width direction, mountability is undesirably deteriorated.